Bilbo joins the dwarves on a adventure to retrieve the Dwarves' gold from Smaug. On their way they bump into some trolls where Bilbo and the dwarves are captured and would have been eaten if it weren't for Sun rise.
Bilbo then finds swords in their cave which they claim and then arrive in Rivendell where Elrond deciphers both what the words on their swords mean and translates the moon letters on the map.
The party then leave and enter the Misty Mountains and are captured by the Goblins(or Orcs as they are called in the Lord of the Rings) and taken to the Great Goblin, where they are once again saved by Gandalf who frees them. On there way out Bilbo falls off one of the dwarves' backs and lands in Gollum's cave where he plays riddles with him with the goal of winning and getting a way out.
Bilbo eventually escapes and meets up with the dwarves but soon after meet up with the Goblins and wargs and are saved by The Eagles and dropped off at the edge of Mirkwood forest.
Gandalf then parts there company to go on other business, leaving Bilbo to protect the dwarves' in mirkwood. Bilbo then saves them from the Spiders and when he next sees them he has to save them again this time from the Wood Elves.
After that they arrive at the edge of the Lonely Mountain. He eventually find the secret door and Bilbo goes in discovers Smaug's weakness and quickly escapes. Smaug the buries them into the mountain and desends on the villiage below. Bilbo tells the Thrush to tell Bard of the hole in his armor and Bard uses this to kill him.
The Dwarves then take control of the mountain once more but then go to war with the Men and Wood Elves. This war is interruped by the arrival of the Goblins...The 3 then make a truce to defeat them and are saved by the arrival of the Eagles making this The Battle of the 5 Armies.
After this Bilbo returns home placing his ring on the mantle piece with Gandalf finishing the movie with this line, "It is not the end but only the beginning."